In certain disease states, the heart lacks sufficient pumping capacity to maintain adequate blood flow to the body's organs and tissues. For example, conditions such as ischemic heart disease and hypertension may leave the heart unable to fill and pump efficiently. This condition, also called congestive heart failure, may lead to serious health complications and even death. In fact, congestive heart failure is one of the major causes of death in the Western world.
This inadequacy of the heart can be alleviated by providing a mechanical pump also referred to as a ventricular assist device (“VAD”) to supplement the pumping action of the heart. VADs may be used to assist the right ventricle, the left ventricle, or both. For example, a VAD may assist the left ventricle by mechanically pumping oxygenated blood from the left ventricle into the aorta. In this case, the pump is implanted within the body of the patient so that an inflow opening of the pump communicates with the left ventricle, and an outflow opening of the pump communicates with the aorta. The pump receives blood from the left ventricle and then pushes it into the aorta for distribution throughout the body. This reduces the strain on the heart by reducing the volume of blood that the heart is responsible for moving. A VAD having an inflow opening communicating with the right ventricle and an outflow opening communicating with a pulmonary artery may be used to assist the right ventricle.
U.S. Pat. Nos. 7,575,423, 7,976,271, 8,007,254, and 8,419,609, the disclosures of which are hereby incorporated by reference, disclose certain rotary blood pumps which can be used as ventricular assist devices. These pumps are electrically powered. Typically, these and other electrically powered implantable pumps are connected through a cable, commonly referred to as a “driveline,” to a control device which supplies electric power to the pump and controls its operation. The control device is often external to the patient's body, in which case the driveline must extend out of the body via a skin opening. The control device must usually provide continuous electric power over the driveline. This power must be provided at relatively high current (0.5-2.0 Amps) and moderate voltage (3-40 Volts) for extended periods of time, such as years or decades, without losing electrical continuity and creating heat losses due to resistance that would cause physiological complications.
The driveline must withstand movement of the surrounding body tissues and contamination by body fluids. Separable connectors generally have been regarded as not providing the requisite combination of current carrying capacity, reliability and durability in this demanding environment. The drivelines used heretofore typically have been made as continuous cables, without any separable connections at least in that portion of the driveline that extends within the body of the patient.
Because any skin opening provides a natural means for bacteria or other contaminants to enter the body, infections can occur at the skin opening. If such an infection occurs, then it may become necessary to remove or replace the driveline from the skin opening to permit proper treatment of the infection. Where the driveline is a continuous element, there is presently no way to effect these treatments without subjecting the patient to a major surgery. Typically, a surgeon must remove the entirety of the existing driveline, including the portion adjacent the VAD, in order to route the new driveline through a new skin opening that is remote from the infection.
It has also been proposed to use implanted control devices that receive power from an external source by means of an implanted induction coil, without a permanent skin-penetrating connection. In such an arrangement, the control device and the entire driveline are disposed within the body. It would be desirable to provide a separable connector at one or both ends of such a driveline to facilitate threading of the driveline through the body during installation.
Therefore, further need exists for improvements in drivelines and connection systems.